measles, mumps and rubella ch 10, 11 & 12. measles highly contagious viral illness first...
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Measles, Mumps and Rubella
Ch 10, 11 & 12
Measles
•Highly contagious viral illness
•First described in 7th century
•Near universal infection of childhood in
prevaccination era
•Remains the leading cause of vaccine-
preventable death in children
•Paramyxovirus (RNA)
•Rapidly inactivated by heat and light
Measles Pathogenesis and Clinical Features
• Respiratory transmission of virus• Replication in nasopharynx and regional lymph nodes• Primary viremia 2-3 days after exposure• Secondary viremia 5-7 days after exposure with spread to tissues• Incubation period 10-12 days• Stepwise increase in fever to 103°F or higher• Cough, coryza, conjunctivitis• Koplik spots• 2-4 days after prodrome, 14 days after exposure• Maculopapular, becomes confluent• Begins on face and head• Persists 5-6 days• Fades in order of appearance
ConditionDiarrheaOtitis mediaPneumoniaEncephalitisHospitalizationDeath
Percent reported876
0.1180.2
Measles Complications
Based on 1985-1992 surveillance data
Measles Epidemiology• Reservoir Human
• Transmission Respiratory Airborne
• Temporal pattern Peak in late winter–spring
• Communicability 4 days before to 4 days after rash onset
Measles Vaccine• Composition Live virus• Efficacy 95% (range, 90%-98%)• Duration of
Immunity Lifelong• Schedule 2 doses• Should be administered with mumps and rubella as
MMR, or with mumps, rubella and varicella as MMRV
• 1941 - 894,134 U.S. cases• 1995 - 288 U.S. cases
•Infants vaccinated at <12m who were born to naturally-infected mothers may not develop sustained antibody levels when later revaccinated
•Primary failure–No seroconversion
•Secondary failure–Loss of protection after seroconversion
Vaccine Failure
Measles VaccineIndications for Revaccination
• Vaccinated before the first birthday
• Vaccinated with killed measles vaccine
• Vaccinated prior to 1968 with an unknown type of vaccine
• Vaccinated with IG in addition to a further attenuated strain or vaccine of unknown type
Mumps
• Acute viral illness
• Parotitis and orchitis described by Hippocrates in 5th century BC
• Viral etiology described by Johnson and Goodpasture in 1934
• Frequent cause of outbreaks among military personnel in prevaccine era
Mumps Virus
• Paramyxovirus
• RNA virus
• One antigenic type
• Rapidly inactivated by chemical agents, heat, and ultraviolet light
Mumps Pathogenesis
• Respiratory transmission of virus
• Replication in nasopharynx and regional lymph nodes
• Viremia 12-25 days after exposure with spread to tissues
• Multiple tissues infected during viremia
Mumps Clinical Features
• Incubation period 14-18 days
• Nonspecific prodrome of myalgia, malaise, headache, low-grade fever
• Parotitis in 30%-40%
• Up to 20% of infections asymptomatic
CNS involvement
Orchitis
Pancreatitis
Deafness
Death
15% of clinical cases
20%-50% in post- pubertal males
2%-5%
1/20,000
Average 1 per year (1980 – 1999)
Mumps Complications
Mumps Epidemiology• Reservoir Human
Asymptomatic infections may transmit
• Transmission Respiratory drop nuclei
• Temporal pattern Peak in late winter and spring
• Communicability Three days before to four days after onset of active disease
Mumps Outbreak, 2006
• Source of the initial cases unknown
• Outbreak peaked in mid-April
• Median age of persons reported with mumps was 22 years
• Highest incidence was among young adults 18-24 years of age, many of whom were college students
• Transmission of mumps virus occurred in many settings, including college dormitories and healthcare facilities
MMWR 2006;55(42):1152-3
Factors Contributing To Mumps Outbreak, 2006
• College campus environment• Lack of a 2-dose MMR college entry requirement or lack
of enforcement of a requirement
• Delayed recognition and diagnosis of mumps• Mumps vaccine failure• Vaccine might be less effective in preventing
asymptomatic infection or atypical mumps than in preventing parotitis
• Waning immunity
Passive immunization against mumps
– Immune globulin ineffective for postexposure prophylaxis
• does not prevent disease or reduce complications
– Transplacental maternal antibody appears to protect infants for first year of life
Mumps Vaccine• Composition Live virus (Jeryl Lynn strain)
• Efficacy 95% (Range, 90%-97%)
• Duration ofImmunity Lifelong
• Schedule >1 Dose
• Should be administered with measles and rubella (MMR) or with measles, rubella and varicella (MMRV)
Rubella• From Latin meaning "little red"
• Discovered in 18th century - thought to be variant of measles
• First described as distinct clinical entity in German literature
• Congenital rubella syndrome (CRS) described by Gregg in 1941
Rubella Virus• Togavirus
• RNA virus
• One antigenic type
• Rapidly inactivated by chemical agents, ultraviolet light, low pH, and heat
Rubella Pathogenesis
• Respiratory transmission of virus
• Replication in nasopharynx and regional lymph nodes
• Viremia 5-7 days after exposure with spread to tissues
• Placenta and fetus infected during viremia
Rubella Clinical Features• Incubation period 14 days
(range 12-23 days)
• Prodrome of low-grade fever
• Maculopapular rash 14-17 days after exposure
• Usually quite mild
Epidemic Rubella – United States, 1964-1965
• 12.5 million rubella cases• 2,000 encephalitis cases• 11,250 abortions (surgical/spontaneous)• 2,100 neonatal deaths• 20,000 CRS cases
– deaf - 11,600– blind - 3,580– mentally retarded - 1,800
Congenital Rubella Syndrome
• Infection may affect all organs• May lead to fetal death or premature delivery• Severity of damage to fetus depends on
gestational age• Up to 85% of infants affected if infected during
first trimester
Congenital Rubella Syndrome
• Deafness
• Cataracts
• Heart defects
• Microcephaly
• Mental retardation
• Bone alterations
• Liver and spleen damage
Rubella Epidemiology
• Reservoir Human
• Transmission Respiratory Subclinical cases may transmit
• Temporal pattern Peak in late winter and spring
• Communicability 7 days before to 5-7 daysafter rash onsetInfants with CRS may shed
virus for a year or more
0
10000
20000
30000
40000
50000
60000
70000
1966 1970 1975 1980 1985 1990 1995 2000 2005
Rubella Cases
0
10
20
30
40
50
60
70
80
CRS Cases
Rubella CRS
Rubella - United States, 1966-2005
Year
Rubella Vaccine• Composition Live virus (RA 27/3 strain)
• Efficacy 95% (Range, 90%-97%)
• Duration ofImmunity Lifelong
• Schedule At least 1 dose
• Should be administered with measles and mumps as MMR or with measles, mumps and varicella as MMRV
Rubella Vaccine Arthropathy• Acute arthralgia in about 25% of vaccinated,
susceptible adult women• Acute arthritis-like signs and symptoms occurs in
about 10% of recipients• Rare reports of chronic or persistent symptoms• Population-based studies have not confirmed an
association with rubella vaccine
Vaccination of Women of Childbearing Age
• Ask if pregnant or likely to become so in next 4 weeks
• Exclude those who say "yes"
• For others– explain theoretical risks– vaccinate
Vaccination in Pregnancy Study 1971-1989
• 321 women vaccinated
• 324 live births
• No observed CRS
• 95% confidence limits 0%-1.2%
Measles Mumps Rubella Vaccine
• 12 -15 months is the recommended and minimum age (more effective at 15 months)
• MMR given before 12 months should not be counted as a valid dose
• 2nd dose at 4-6 years
MMR Adverse Reactions• Fever 5%-15%
• Rash 5%
• Joint symptoms 25%
• Thrombocytopenia <1/30,000 doses
• Parotitis rare
• Deafness rare
• Encephalopathy <1/1,000,000 doses
MMR Vaccine and Autism
• Measles vaccine connection first suggested by British gastroenterologist
• Diagnosis of autism often made in second year of life
• Multiple studies have shown NO association
MMR VaccineContraindications and Precautions
• Severe allergic reaction to vaccine component or following prior dose
• Pregnancy
• Immunosuppression
• Moderate or severe acute illness
• Recent blood product
Measles and Mumps Vaccines and Egg Allergy
• Measles and mumps viruses grown in chick embryo fibroblast culture
• Studies have demonstrated safety of MMR in egg allergic children
• Vaccinate without testing
Measles Vaccine and HIV Infection
• MMR recommended for persons with asymptomatic and mildly symptomatic HIV infection
• NOT recommended for those with evidence of severe immuno- suppression
MMR Vaccines
Component, per 0.5 ml dose
Measles (Attenuvax) Merck
Mumps Jeryl Lynn Strain Merck
Rubella (Meruvax) Merck
MMR-II Merck
Measles virus >1,000 TCID 50
>1,000 TCID 50
Mumps virus >20,000 TCID 50 >20,000 TCID 50
Rubella virus >1,000 TCID 50
>1,000 TCID 50
Sorbitol 14.5 mg 14.5 mg 14.5 mg 14.5 mg
Sodium phosphate
Sucrose 1.9 mg 1.9 mg 1.9 mg 1.9 mg NaCl
Gelatin 14.5 mg 14.5 mg 14.5 mg 14.5 mg Human albumin
0.3 mg 0.3 mg 0.3 mg 0.3 mg
Fetal bovine serum
<1 ppm <1 ppm <1 ppm <1 ppm
Neomycin ~25μg ~25μg ~25μg ~25μg